Retrieve the variable type of a distribution, such as "continuous" or "discrete".
Examples
vtype(dst_beta(1, 2))
#> [1] "continuous"
vtype(dst_bern(0.4))
#> [1] "discrete"
vtype(distribution())
#> Warning: Full suite of distribution properties may not be accessible without specifying 'cdf', and either 'density' or 'pmf'.
#> [1] "unknown"
